Bacterial chemotaxis, the movement toward or away from chemicals, requires methionine for the methylation of a membrane protein. The proposed work concerns a study of this methylation: to purify and characterize this methylated protein, and to understand the methylation of demethylation reactions. In addition, we hope to learn which of several chemotaxis genes are responsible for synthesizing each of these activities. Further, we propose to learn the role that a change in membrane potential plays in communication between chemoreceptors and flagella. BIBLIOGRAPHIC REFERENCES: Chemotaxis in bacteria. J. Supramolecular Structure 4, 305-317 (1976). J. Adler. The sensing of chemicals by bacteria. Scientific American 234, 40-47, (1976). J. Adler.